I just finished Nicky Barnes' autobiography, he talks a bit about Matty Madonna. They got close in Green Haven prison while Madonna was doing time for murder. Sounds like he was living pretty decently in there. Not like the wiseguys were in Goodfellas, but still pretty good. According to Barnes, Madonna's supplier (didn't know who) dried up so Madonna tried to start his own thing importing from Thailand. He didn't have enough layers of separation from him and the drugs so he got busted.

Barnes also says Matthew had an older brother Frank who was his original source of heroin. Don't know what happened to him.